Treatment of material in a vacuum and apparatus



O. MINTON TREATMENT OF MATERIAL IN A VACUUM AND APPARATUS Aug. 10

ofiginal Filed March l, 1920 I III" ATTORNEY memesugie 1926.

PATENT OFFICE.

v UNITED-STATES.

oennn Env ron, or ennnnwron, CONNECTICUT.

TREATMENT OF MATERIAL: IN A VACUUM AND AIPI'AIBA'IU'S.

Original application filed larch"4, 19.20, SeriaI' nofaeaasi;

* 20, 1922, Serial No. 545,213.

This application is a division of-my copeuding application Treatment. of material in a vacuum and apparatus, filed March 4, '1920,',Ser. No. 363,351, case G.

Thepresent invention relates to an appa-' drying of paper vacuum chamber, Wh le still 1n the or coloring, or

vacuumchamber through a liquid sealing .medium which has no afiinity for the material, subjecting it to heat to drive ofl its contained moisture, immediately coating or coloring, or sizing or impregnating the ma? terial while in the vacuum chamber, then subjecting the-coated or colored, or sized or impregnated material to heat to drive off its contained moisture or otherliquid, and then passing the material out of the chamber .through aseal.

' This method may be practiced by the use of various forms of apparatus, some of which are herein disclosed In any form, 'however, it is emential thatthe apparatus be provided with a closed chamber in which a partial vacuum may be maintained. In order that the material to be dried, treated, and again dried may be continuously passed through the vacuum-chamber, the latter is provided with openings closed to the admission of airby' a liquid sealing medium which has no afl'mity for the material. The

liquid seal efi'ectively closes the entrance and exit passages against the admission of air to the chamber, but permits the passage of the material into and out ofthe chamber.

-,Any other sealing means may be used.

My invention further relates to withdrawing from the sheet material substantially all, or a large portion, of its occluded air and filling the interstices normally filled by the occluded'air with a coating or impre nating compound, and then drying said the paper or other Divided and this application filed March Renewed February. 17, 1926.

coated or impregnated sheet material in the vacuum chamber before subjecting the said sheet material to atmospheric conditions.

My invention further relates 'to obtaining a better and more uniform product than any now known on the market. My invention further relates to the method of coating or impregnating sheet material which insures that therewillbe no blemishes, uneven surfaces, blisters or minute raised portions due "to the air which may be held or occluded Within the sheet material, which, in the present practice-of coating as for example with a waterproof compound, leads to rejections or discards due to these imperfections with the consequent waste of material and labor.

My invention further relates to the treatment of paper, either from the wet end-of a paper machineor from a roll or reel ofwet or damp paper, feeding theweb of wet or amp paper into a vacuum chamber without breaking the vacuum, drying said web;

in the vacuum chamber and removingsubstantially all of its occluded air, and. immediately coating or impregnating or colorng or sizing said dry web with a coating or lmpregnating or coloring or sizing compound, and then again drying the web, the second time with its coating or impregnat= ing or coloring or sized compound, Within the vacuum chamber and all these steps being continuous and coated or impregnated compound to the action of the atmosphere.

My mvention further relates to manufacturing paper wherein thefibers are'notweakened and the'siz'e in the paper is not prior to subjecting the mjured or damaged due to drying at highteriilieratums.

y invention further relates to manufac turingcolored paper and drying it without substantially impairing the coloring matter and mordants which will be substantially uni orm in different runs of pa er, permitting matching'of colored paper Without any appreciable diiference in tone or color.

My invention further. relates to rapidly used in the paper. Among other advantages this insures that the paper will have bright colors,

I I and eztpeditiou'sly coating or impregnating sheet material in a continuous web or sheet. My invention further relates to sizing paper in a vacuum chamber and drying the 'sized paper in said vacuum chamber at such low temperatures as notto injure the fibers of the paper or the size; My invention further relates to withdrawing the occluded air from the paperand immediately drying and then filling the interstices normally filled with the occluded air with the size, and then drying the thoroughly sized paper in the vacuum chamber before it is subjected to atmospheric conditions. My invention further relates to carrying out this nethod continuously with a continuous web of paper then while still in the vacuum chamber, coating, coloring, sizing or impregnating the material; then drying the coated, sized, colored or impregnated material while still in the vacuum chamber, and preferably while under not sufficient tension to substan-' tially rearrangeits constituent. elements; and. then' continuously passing the dry coated, impregnated, colored or{,sized material out of the vacuum chamber without breaking'the vacuum.

My invention further relates to certain steps, and combinations of steps, also to certain elementsand combinations of' elements, whereby the method or processes herein described may be carried .out, as well as to certain details of construction, all of which wilPbe more fully hereinafter described in the specification and pointed out in the claims. In these-drawings the same reference numerals refer to similar parts in the several figures. i

Fig. 1 is a vertical diagrammatic section of one form'of apparatus which may be used to carry out my improved method; v

Fig. 2 is a vertical diagrammatic section of a Il'lOdlfiCiltlOlLlIl which the material is V heated by one or more electric heaters.

will describe the form of In describing my invention I 1t as applied to material in paper though it is to be distinctly under' i such high heat is used as stood that textile fabrics may also be treated by my process and that my broader claims cover. all forms of materials.

In the ordinary drying of a web of paper to inj uriously effect the fibers of the paper; and in case the paper is colored it will materially effect the coloring matter and mordants used.- Drying paper in the high temperatures used in ordinary practice often efiects the size so that the resulting paper varies in quality, is not uniform and is not a'per'fect product.

In coating or impregnating fabrics. it is found in practice that the coated fabric Will frequently have blemishes due to large or slnall'blisters and blow holes, these often being about the size'of a pin-head or av pinpoint. This is caused by the air-which is held or occluded being collected, more or less, in. small pockets under impregnating material, or in some cases causing 'minute blow holes. In waterproof fabrics this results in large quantities of the material being-rejected'with the consequent loss to the manufacturer.

y y tially all the occluded air is withdrawn from the sheet material which will permit the coating ,or irnpregnating material, whatever "it may be, to thoroughly fill these minute the coating or v nvent'on I .nsurethat substaninterstices or pockets normally occupied by occluded air, forming thereby a better an more dniform" product and one devoid of blisters, blow holes or such blemishes. By my invention I immediately dry such coated or impregnated-sheet material while still in the vacuum chamber so that when the sheet material emerges from the vacuum chamber the coating or impregnating material is dry and set without any dangerof atmospheric pressure or atmospheric conditions spoiling or marring the finished product.

As reviously stated I will describe my invention with relation to coating or impregnating paper, though it is to be understood that textile fabrics may be treated in the same manner.

In the ordinary commercial paper making machine the fibers of the paper stock or furnish are formed on the wire of the machine. There they are interlaced and locked, more or less, firmly together. Taking the wet web from the wire of the paper machineandrunning it over a series of heated drying drums or c linders tends to pull the fibersin the direction of travel of the heated rollers, cylinders or driers as they are technically known. The more pull on the Wet web, the more the fibers tend to straighten out in the direction of travel of the heated cylinder or drier which is drying the Web and moving at high speed. Each succeeding drier tends to augment this pulling of the fibers of the paper.

This not only results in the web shrinking the wire of the paper machine,

This results in the sheet being as strong lengthwise of the sheet as it is crosswise of the sheet, This is not true where considerable tension has been placed on the wet web by passing over large drying-drums orcylinders. It is, therefore, obvious that anew result is accomplished.

- A coated, colored, sized'or impregnated paper of a given strength is obtained with relatively poor stock or furnish. To obtain a coated. colored, sized or impregnated paper of thesamc strength made by a method in which the fibers of the paper were not permitted to dry at random, or substantially as formed on the wire of the paper machine, would require much better and more expensive stock or furnish. I

By my invention the material is fed through the vacuum. sufficient pull or tension to insure its passage and without substantially causing the constituentelements of thematerial to rearrange themselves from their original position.

Various means may be used to feed the material into and out of the vacuum chamber without breaking the vacuum and still come within the terms of my invention as previously explained.

'For example the web of paper 1 is fed direct from the wet end of a paper making machine, or in some cases it may be fed from a roll or reel 20f wet or damp paper. The Web is fed into the vacuum chamber A by passing over the guide roller f1, into the liquid seal' '5, under the submerging roller 6, and thence in contact with the guide roller 7. This liquid seal 5' maybe of any suitable material which has no atfinity for the sheet material treated and has no deleterious eifectupon it. Preferably I use mercury as the'sealing medium 5, but it is to be distinctly understood that any amalgam, alloy, or any other suitable liquid sealing medium may be employed which has the characteris tics above specified.

The web 1 is immediately upon its entry into the vacuum chamber A dried preparatoryto coating or coloring or sizing or impregnating it; but it is dried in a manner which does not Weaken it or cause its fibers to substantially rearrange themselves from the position assumcdby them on the wire of the paper making machine.

I have shown the web of paper passing through the vacuum chamber A in folds or loops, passing under the guide rolls 8, 8 and over the guide rolls 9, 9. Preferably I heat the .web, or other material, as it passes through the'vacuum chamber A, but in a manner which will notcause the fibers to be substantially weakened 'or pulled out in the direction of travel of the web. I provide one or more fixed heaters 10, 10

preferably located in the folds or loops but passed through chamber under ust oring, sizing pregnating. bath 12 not touchin wine of the web as it is crosswise of the we).

.The web 1 is then immediately passed through the coating, impregnating, coloring or sizing bath 12 in the chamber 13, passing underthe submerging roll 14. It is then the squeeze rolls 15, '15 to the guide roll 16.

The web is again dried before passing out of the vacuum chamber. Different drying means maybe used to dry the coated or clored, or sized or impregnated web than the means used to drythe wet webbefore it passed through the bath 12. Preferably, however, I use duplicate drying means which will insure that little or no tension be placed on the web, the tension not being suflicient to substantially causethe fibers to rearrange themselves from the positionassumed by them on the wire of the paper making machine.

I have shown in Fig.1 the second drying means as a duplicate of the first. That is as the coated, impregnated, colored or sized web 1 (passes over the guide roll-16 it is led in fol s or loops through the right hand portion of the vacuum chamber under the guide rolls 17, 17 andover the guide rolls 18, 18. One-or more of these folds or loops are heated by the steam radiators 10, In. Only sufiicient pull or tension is placed on thoroughlydry and the web will be substantially ;as strong length the web to feed it through the vacuum chamber A. 1

' When the web-has reached the guide roll 19 it is completely dry and the coating, color impregnating material is dry and set. It is then vacuum chamber through the exit seal 5 under the submerging roll 20, over the guide roll 21. It ma then be cut, stacked or rolled into a roll of nished material 22.

In Fig. 2 I'have shown a modification of my invention in which I use electric heaters 23, 23 instead of the steam radiators 10,10 to heat the material as it passes through the yacuum chamber before, and also preferably after, passing through bath may be of any suitable material to coat or impregnate, or .color sheet material Simwhether it be paper or textile fabric. ply by way'of example, this coating or'immaybe size, tar, wax, or in fact any coating or waterproofing, or impregnating or coloring compound.

The vacuum chamber A is provided with pipes 24, 24 leading to any suitable form' of vacuum apparatus. .I also referably provide the vacuum chamber witli Windows 25, 25 so that the'operator can at all times the bath 12. This passed out of the 1 the cock 29.

to the bath 12 by the plpe In some cases the coating, coloring, impregnating or sizing bath 12 may see into the interior of the vacuum chamber. The chamber 13 in which the bath 12 is located can be drained by the pipe 26 and cock 27. Additional liquid 28 controlled by 7 to leaks in the piping system, and other indried at atmospheric pressure, when the paper carefull of the wet paper efficiencies, it has been shown in practice that about 10,600" pounds are required.

In my method, using a vacuum of about 28", the convection, conduction and piping losses are exceedingly small andthe total steam required to dry, a ton of paper by my method is approximately520l) pounds.

It is an established fact that paper dried at low temperatures is muclr stronger than when it is dried at the high temperatures used in paper machine atmospheric drying. Paperdried in a vacuum of 28', or at a temperature of about 100 F.,-as in my method, is very much stronger than paper steam in the driers is at 228 F. hen paper is dried by my method, therefore, a cheaper furnish or stock can be used and still produce a coated or impregnated or colored or sized paper equal in strength to atmospheric dried paper, in which a higher grade furnish or stock is used. In making newsprint paper, I am able to dispense with a considerable portion of the more expensive sulphite pulp, as thiscan be replaced with the cheaper ground wood pulp. By my method I also reduce the number of breaks in the web as it passes over the cylinder.

Furthermore, in my method there is a great saving of heat (or steam) because the process is carried on in a vacuum. chamber which acts on the principle of a" thermos bottle, and the steam and vapors driven out are caught in the closed vacuum chamber, and conducted away to thecondenser. The operating room is free from steam, humldity and heat, and fans,

and exhausters are dispensed with. In the use of my method the apparatusis at all times operating under definite humidity,the control of the drying can be closely standardized, and the 'moisture. content in the y regulated.

Having pointed out the many advantages of my method and apparatus-over those heretofore used, it will be apparent that the large savings can be supplied 1 ,to materially rearrange use of my invention results in great economy in the initial cost of apparatus and in in cost of operation, maintenance and repairs. 1 Having thus described this invention in connection WitlffillllStlittiVG embodiments thereof, to the details of which I do not desire to be limited, what is claimed as new and what is desired to secure by Letters Patent is set forth in the appended claims.

What I claim is 1. The method of treating porous material in a web consisting in feeding it into and out .of a vacuum chamber. without breaking the vacuum, drying the material in the vacuum chamber while under little or no tension so as to permit the constituent elements.

of the porous material to dry while under little or no tension, coating or impregnating the dry porous material, and then. drying the coated or impregnated porous material in the vacuum chamber. 0'

2. The method of treating sheet material consisting in feeding it into and out of a vacuum chamber without breaking the vacuum, drying the sheet material in the vacuum chamber in a manner which will per.- rnit the constituent elements of the sheet material to dry while under little or no tension, coating or impregnating the dry sheet material, and then drying the coated or impregnated sheet material in the vacuum chamber in a mannerwhich will permit the constituent elements of the coated or impregnated sheet material to dry substantially in-their original relative positions.

3. The method of-treating a web of sheet material consisting in feeding it into a vacuum chamber through a liquid seal that has no affinity for, ordeleterious effect upon said web of sheet material, drying said web in the vacuuimchamber by permitting its constituent elements to shrink or dry with little or no tension upon them,' coatif1g or impregnating said web in thevacuum cham ber, drying said coated or impregnated web while still in the-Vacuum-chamber, and then passing said dry and coated or impregnated web out of the vacuum chamber through a liquid seal that has no affinity for or dele-' terious efiect upon said coated or impregnated web. v

4. The method of treating a wet web of paper consisting in continuously feedingithe wet web into and out of a vacuum chamber without breaking the vacuum, drying-the web in the vacuum chamber under little or no tension, the ten'sionnot being sufficient the fibers of the paper from their original matted or interlaced position on the wire} of the paper machine thereby, obtaining {a web or sheet of paper substantially as strong lengthwise of the sheet as it is crosswise of the sheet, then" continuously while still in the vacuum chamber coating, or sizing, or coloring or impregnating the web of paper, and then while still in the vacuum chamber, drying 'said coated, sized, colored or impregnated web of paper before it is atmosphere.

5. The method of paper consisting in continuously feeding the Wet web into and out of a vacuum chamber without breaking the Vacuum, drying the web in the vacuum chamber under little or no tension, the tension not being suflicient to materially rearrange the fibers of the paper from their original matted or interlaced position on the wire of the paper machine, thereby obtaining a web or sheet of paper substantially as strong lengthwise of the sheet as it is crosswise of the sheet, then continuously while still in the Vacuum chamber coating, or "sizing or coloring or impregnating the web of paper, and then while still in the vacuum chamber again drying said web while under little or no passed into the tension, the tension not being suflicient to substantially rearrange the fibers of the paper from their original position on the wire of the paper machine, and then continuously passing the dry coated or im-' pregnatedor colored, or sized paper out of the vacuum chamber without breaking the vacuum.

6. The method of treating a web of paper consisting in feeding the wet web into a vacuum chamber through a liquid seal which has no aflinity for or deleterious effect upon said web, continuously drying the web in the vacuum chamber by permitting its fibers to dry while under little or no tension to form a web as strong lengthwise as cross- Wise of the sheet, continuously sizing the web in the vacuum chamber, continuously drying the sized web in the vacuum chamber by passing the sized web of paper in folds or loops through the vacuum chamber, and continuously withdrawing the dry and sized web from the vacuum chamber through a liquid seal that has not aflinity for or deleterious efiect upon said web;

7. An apparatus for treating porous matreating a wet web of terial including a Vacuum chamber, means to permit the porous material to pass into and out of the said chamber without breaking the Vacuum, drying means mounted in the vacuum chamber adapted to permit the porous'material to be dried without substantially rearranging the constituent elements of the porous material from their original position, coating, sizing, coloring or impregna-ting means mounted in the vacuum chamber, and additional drying means mounted in the vacuum chamber to dry the coated, impregnated, colored or sized porous material prior to its passage into the atmosphere.

8. An apparatus for treating porous material including a vaccum chamber, means to permit the porous material to pass into and out of the said chamber without breaking the vacuum, drying means mounted in the vacuum chamber adapted to permit the porous material to be dried in folds or loops without substantially rearranging the constituent elements of the porous material from their original position, coating, sizing, coloring or impregnating means mounted in the vacuum chamber, and additional drying means mounted in the vacuum chamber to dry the coated, impregnated, colored or sized porous material prior to its passage into the atmosphere, and without substantially rearranging its constituent elements.

9. An apparatus for treating paper including a vacuum chamber, liquid seals closing the entrance and exit passages to said chamber, said seals having no atfinity for or deleterious effect upon the paper treated, drying means mounted in the vacuum chamber which permit the constituent elements of the paper to dry at will or at random, coating or sizing or coloring or impregnating means mounted in, the vacuum chamber, and additional drying means mounted in the Vacuum chamber adapted to dr the coated, impregnated, colored or size paper withoutsubstantially rearranging its constituent elements or fibers.

. OGDEN MINTON. 

